Operation planning method, and heat pump hot water supply and heating system operation method

ABSTRACT

An operation planning method performed in a system including a power generation device, a first electric load operating using power generated by the power generation device, and a second electric load which generates heat using power generated by the power generation device. The operation planning method is performed to design an operation plan for the second electric load and includes: predicting, for individual unit time periods, a power generation amount by the power generation device and a power consumption amount by the first and second electric loads; and designing the operation plan for the second electric load to operate during an operation period including the time period with the largest amount of reverse power, calculated by subtracting the first and second power consumption amounts from the power generation amount.

TECHNICAL FIELD

The present invention relates to a device relating to power generationsuch as a photovoltaic device (solar power generation device), and to asystem which includes a device that consumes power such as a heat pump.

BACKGROUND ART

Power generation devices, such as a solar or wind power generationdevices, are devices designed to create energy. Solar power is generatedby transforming solar energy into electricity and is supplied to homesas a natural source of energy. The amount of power generationcontinuously fluctuates with weather and meteorological conditions.

A heat pump hot water heater heats a refrigerant by absorbing heat fromthe atmosphere and compressing the refrigerant using electricity, andthen transfers the heat to the water via a heat exchanger, therebycreating hot water. With this method, the hot water supply system usesless energy than with an electric hot water heater in which heating isdone by an electric heater.

The heat pump hot water supply system including the power generationdevice constitutes a combination of the above devices, and supplies aconsumer with power and heat. An example of a conventional heat pump hotwater supply and heating system including a power generation device isdisclosed in PTL 1.

PTL 1 discloses an invention which obtains weather forecast informationfrom a server using a weather information obtaining means, and switchesto use solar generated power to boil the water in the CO₂ heat pump hotwater heater instead of late night power from a commercial power sourcewhen the obtained information is set up as a condition for operation.Operating using power harnessed from natural energy allows for a powerefficient, low-energy electric hot water heater which can reduceelectricity costs.

CITATION LIST

-   [PTL 1] Japanese Unexamined Patent Application Publication No.    2008-2702-   [PTL 2] Japanese Unexamined Patent Application Publication No.    2006-158027

Technical Problem

However, the conventional device does not take into consideration theamount of consumption of the reverse power derived from the constantlyfluctuating photovoltaic device and an electric load of the consumer. Asa number of homes simultaneously generating reverse power increases withthe growing prevalence of solar power generation, the voltage of a powergrid will increase, causing the grid to become unstable. Moreover, theconsumer, who is located on the downstream side of the grid, cannot flowreverse power when the voltage of the grid is high, causing the powergenerated by the photovoltaic device to go to waste.

Moreover, the voltage of the reverse power is converted according to theelectricity distribution system which causes a significant conversionloss in the process. Transmitting the power to another consumer alsocauses a transmission loss in the process as well. As such, it is moreenvironmental for the consumer to consume the generated power onlocation.

Furthermore, with the device proposed in PTL 2, the heat pump unit isoperated when the amount of generated power exceeds the amount of powerused. However, the heat pump unit is not operated in response to theamount of excess power, nor does it effectively reduce the amount ofpower flowing in reverse to the grid.

The present invention is conceived to solve the above-described problemsand is designed to provide an operation planning method for a systemincluding a power generation device in which the system maintains alow-energy performance characteristic and reduces the amount of reversepower.

Solution to Problem

An operation planning method according to the first embodiment of thepresent invention is performed in a system including a power generationdevice, a first electric load which operates using power generated bythe power generation device, and a second electric load which generatesheat using power generated by the power generation device, the secondelectric load including a heat generation unit which generates heatusing power generated by the power generation device, the operationplanning method being performed to design an operation plan for thesecond electric load. Specifically, the second electric load includes aheat generation unit which generates heat using power generated by thepower generation device, a heat storage unit which stores heat generatedby the heat generation unit, a first radiator unit which radiates heatstored in the heat storage unit, and a second radiator unit whichdirectly radiates heat generated by the heat generation unit. Theoperation planning method comprises: predicting, for individual unittime periods, an amount of power to be generated by the power generationdevice, a first amount of power to be consumed by the first electricload, and a second amount of power to be consumed by the heat generationunit to generate heat to be radiated by the second radiator unit; anddesigning the operation plan for the second electric load to cause thesecond electric load to operate during an operation period whichincludes, among the time periods, a time period in which an amount ofreverse power is the largest, the reverse power being calculated bysubtracting the first amount of power to be consumed and the secondamount of power to be consumed from the amount of power to be generated.

With this configuration, damage to a power grid can be reduced bypredicting a time period in which the amount of reverse power will peak,and operating the second electric load in the predicted time period.

The power generation device may be a photovoltaic device, for example.In the predicting, an amount of heat to be radiated in reverse flowstandby by the first radiator unit during a reverse flow standby timeperiod is further predicted, the reverse flow standby time period beinga time period in which the amount of power to be consumed exceeds theamount of power to be generated, and in the designing, an operation planfor the heat generation unit to operate during the operation period isdesigned such that an amount of heat is stored in the heat storage unit,the amount of heat corresponding to the amount of heat to be radiated inreverse flow standby as predicted by the predicting unit.

Moreover, in the designing, the operation plan may be designed for theoperation period which is determined by selecting one or more of thetime periods in descending order of the amount of reverse power until atotal amount of time of the one or more selected time periods exceeds anamount of time required for the heat generation unit to generate theamount of heat corresponding to the amount of heat to be radiated inreverse flow standby.

Moreover, in the designing, a reverse power threshold value may be setto be the amount of reverse power with the lowest value among the one ormore selected time periods, and the operation plan may be designed suchthat operation of the heat generation unit is started at a point in timeat which the reverse power as actually measured becomes equal to orexceeds the reverse power threshold value during the operation period.

In the designing, the operation plan may further be designed such thatoperation of the heat generation unit is stopped at a point in time atwhich the amount of heat corresponding to the amount of heat to beradiated in reverse flow standby is generated during the operationperiod.

Moreover, the heat storage unit may include a thermal storage mediumwhose temperature varies according to the amount of heat stored.Furthermore, the heat generation unit may include a heat pump capable ofheating the thermal storage medium to a first temperature, and a heatercapable of heating the thermal storage medium beyond the firsttemperature. Additionally, in the designing, with respect to the amountof heat corresponding to the amount of heat to be radiated in reverseflow standby, the operation plan may be designed to cause the heat pumpto generate an amount of heat until the thermal storage medium reachesthe first temperature, and cause the heater to generate an amount ofheat after the thermal storage medium reaches the first temperature.

Moreover, in the predicting, the amount of heat to be radiated by theradiator unit during the reverse flow standby time period may bepredicted as the amount of heat to be radiated in reverse flow standby,the reverse flow standby time period being a time period delimited by areverse flow standby start time and a predetermined assumed time atwhich the radiator unit will stop radiating heat, and the reverse flowstandby start time being a time when the amount of reverse power changesfrom a positive value to a non-positive value.

An operation method for a heat pump hot water supply and heating deviceaccording to the first embodiment of the present invention is anoperation method for a heat pump hot water supply and heating systemincluding a photovoltaic device and a heat pump hot water supply andheating device. The heat pump hot water supply and heating deviceincludes a heat pump which generates heat using power generated by thephotovoltaic device, a hot water supply tank which stores hot waterheated using heat generated by the heat pump, and a heating device whichheats a space using heat generated by the heat pump. The system includesan operation planning device. The operation planning device controls thesystem, including: predicting an amount of power to be generated by thepower generation device, a first amount of power to be consumed by anelectric load, and a second amount of power to be consumed by the heatpump to generate heat to be radiated by the heating device; calculatingan amount of reverse power by subtracting the first amount of power tobe consumed and the second amount of power to be consumed from theamount of power to be generated; predicting an amount of heat (theamount of heat to be radiated in reverse flow standby) required in areverse flow standby time period during which the amount of reversepower is zero; and designing an operation plan which causes the heatpump hot water supply and heating device to operate to store thepredicted amount of heat during an operation period which includes atime period in which the amount of reverse power is the largest.

Moreover, in the designing, a heat storage target temperature to storethe predicted amount of heat may be determined and a reverse powerthreshold value may be set to the amount of reverse power with thelowest value among the one or more selected time periods.

Moreover, based on the heat storage target temperature and the reversepower threshold value determined and set in the designing, operation ofthe heat pump hot water supply and heating device may be started at apoint in time at which the reverse power as measured reaches or exceedsthe reverse power threshold value during the operation period, andoperation of the heat pump hot water supply and heating device may bestopped at a point in time at which the predicted amount of heat isgenerated during the operation period.

Moreover, in the designing, the heat storage target temperature forstoring the predicted amount of heat in a hot water supply tank may bedetermined, and a thermal storage medium inside the hot water supplytank may be heated to a first temperature with a heat pump included inthe heat pump hot water supply and heating device, then the thermalstorage medium may be heated to a second temperature which is higherthan the first temperature with a heater installed in the hot watersupply tank.

Moreover, the heat pump hot water supply and heating device includes ahot water supply and heating control device. The hot water supply andheating control device may be set up to receive operation informationfor the heat pump hot water supply and heating device from a remotecontrol as well as from the operation planning device. When receivedfrom the operation planning device, the hot water supply and heatingcontrol device may give the operation information from the operationplanning device priority over the operation information from the remotecontrol, and may control the heat pump hot water supply and heatingdevice based on the operation information from the operation planningdevice.

Moreover, the operation information may be an operation mode for theheat pump hot water supply and heating device, and a hot water supplytemperature setting for the hot water supply tank.

Moreover, the heat pump hot water supply and heating device may furtherinclude a heat exchanger which facilitates heat exchange between arefrigerant in the heat pump and the thermal storage medium, and aswitching device which switches supply of the thermal storage mediumsupplied from the heat exchanger to one of the hot water supply tank andthe heating device. In the controlling, when the switching device isswitched to the heating device and the temperature of the thermalstorage medium is below the first temperature at a point in time atwhich operation of the heat pump hot water supply and heating devicestarts, the switching device may be switched to the hot water supplytank.

Advantageous Effects of Invention

The present invention can reduce damage to a power grid by predicting atime period in which the amount of reverse power will peak, andoperating the system in the predicted time period.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart showing a principle of the present invention.

FIG. 2 is a block diagram of the heat pump hot water supply and heatingsystem including the power generation device according to the firstembodiment.

FIG. 3 is a block diagram of the heat pump hot water supply and heatingdevice.

FIG. 4 is a diagram of the flow of data in the heat pump hot watersupply and heating system.

FIG. 5 is a table showing remote control setting categories and settinginformation.

FIG. 6 is a block diagram of the operation planning device.

FIG. 7 is a table showing a format of the information stored in thestorage means.

FIG. 8 is a graph showing a predicted amount of load power, a predictedamount of heating load power, a predicted amount of photovoltaicgenerated power (hereinafter also referred to as predicted amount ofPV-generated power), and a predicted amount of reverse power for eachtime.

FIG. 9 is a table showing the priority for each time period assigned indescending order by predicted amount of reverse power.

FIG. 10 is a flowchart of an operation planning process.

FIG. 11 is a flowchart of a load prediction process.

FIG. 12 is a flowchart of a control parameter calculation process in theoperation planning means.

FIG. 13 is a flow chart showing an exemplary operation of the heat pumphot water supply and heating system.

FIG. 14 is a flow chart showing another example of an operation of theheat pump hot water supply and heating system.

FIG. 15 is an exemplary graph showing power consumption values underdifferent control methods.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, embodiments of present invention are described withreference to the drawings. As shown in FIG. 1, with the presentinvention, the amount of reverse power is predicted (S104) from theprediction of an amount of load power (S101) which is an amount of powerconsumed within a home, the prediction of an amount of heating loadpower (S102), and the prediction of an amount of PV-generated power(S103) which is an amount of power generated by photovoltaics. The heatpump (hereinafter also referred to as HP) is then made to operate duringa time period with the peak predicted amount of reverse power (S106).The heat pump duration of operation is determined from the predictedamount of hot water supply heat (S105). As a result, the amount of powerflowing in reverse to the power grid can be decreased, and the effectthe power flowing in reverse has on the power grid can be effectivelyreduced.

FIG. 2 is a block diagram explaining a heat pump hot water supply andheating system 9000 including the power generation device. As shown inFIG. 2, the heat pump hot water supply and heating system 9000 accordingto the first embodiment includes a heat pump hot water supply andheating device 900, a power distribution device 905, an operationplanning device 910, and a photovoltaic device 911. The powerdistribution device 905 is connected to a first electric load 906 and apower meter 907 via an energy supplier 908. The operation planningdevice 910 is connected to a server 909 via the Internet.

The energy supplier 908 (source of electric power) as shown in FIG. 2supplies power via a power grid to homes. The power grid is a networkthat provides a stable supply of power. A power meter 907 measures theamount of power supplied via the power grid that is consumed in a home.Moreover, the power meter 907 is set up to consume power generated by aphotovoltaic device 911 in-home, and sell excess power to the grid.

The house shown in FIG. 2 is equipped with the first electric load 906,the heat pump hot water supply and heating device 900 (the secondelectric load), the operation planning device 910, the photovoltaicdevice 911, and the power distribution device 905.

The heat pump hot water supply and heating device 900 includes at leasta heat pump unit 901 a, a heat exchanger 902, a hot water supply device903, and a heating device 904. Here, the hot water supply device (thefirst radiator unit) 903 has an internal hot water supply tank (notshown in FIG. 2) which functions as a heat storage unit. The hot watersupply device 903 stores the heat generated by the heat pump unit 901 a(heat generation unit) in the hot water supply tank, and ejects the hotwater inside the hot water supply tank as requested by a user, that is,radiates the heat stored in the heat storage unit. On the other hand,the heating device 904 (the second radiator unit) is connected to theheat pump unit 901 a via the heating circuit (not shown in FIG. 2), anddirectly radiates the heat generated by the heat pump unit 901 a, thatis, directly radiates the heat without storing it in the heat storageunit.

Moreover, the heat generation unit is connected to the first and thesecond radiator unit via a switching device (three-way valve), anddepending on the setting of the switching device, supplies heat to oneof the first radiator unit and the second radiator unit. In other words,the heat generation unit cannot supply heat to both the first and thesecond radiator unit at the same time.

That is, while the first radiator unit which radiates heat stored in theheat storage unit can radiate heat while the heat generation unit is notoperating or while the switching device is switched to the secondradiator unit, the second radiator unit which directly radiates heatgenerated by the heat generation unit can only radiate heat while theheat generation unit is operating and while the switching device isswitched to the second radiator unit.

The photovoltaic device 911 is a device which converts energy from thesun into electric power. The photovoltaic device 911 converts energyfrom the sun into electric power and outputs the power (PV-generatedpower).

The power distribution device 905 obtains power from the photovoltaicdevice 911 and a commercial power source supplied by the energy supplier908 then distributes the power to the heat pump hot water supply andheating device 900 and the first electric load 906 on demand. The heatpump hot water supply and heating device 900 can operate off power fromthe photovoltaic device 911 as well as off power bought from acommercial power source (grid power).

The power distribution device 905 can measure the amount of powerdistributed to the heat pump hot water supply and heating device 900 andthe first electric load.

The power distribution device 905 obtains the PV-generated power fromthe photovoltaic device 911. The power distribution device 905 measuresthe load power which is power consumed by the first electric load 906,the heating load power which is power consumed by the heat pump hotwater supply and heating device 900 in order to generate heat to beconsumed by the heating device 904, and the hot water supply power whichis power consumed by the heat pump hot water supply and heating device900 in order to generate heat to be consumed by the hot water supplydevice 903. When the sum of the load power, the heating load power, andthe hot water supply power exceeds the PV-generated power, powerpurchased from the power grid is obtained via the power meter 907. Thatis, the power distribution device 905 obtains the PV-generated power andthe purchased power, then supplies the heating load power and the hotwater supply power to the heat pump hot water supply and heating device900, and the load power to the first electric load 906. Moreover, whenthe PV-generated power exceeds the sum of the heating load power, thehot water supply power, and the load power, surplus power can betransmitted as reverse power and sold to the energy supplier 908.

The power distribution device 905 also includes a converter and inverterwhich, when obtained power is transmitted as described above, convertsthe voltage and performs AC-DC and DC-AC conversion of the obtainedpower accordingly so the obtained power conforms to the transmittedpower. Moreover, the power distribution device 905 transmits the loadpower actually consumed by the first electric load 906 and thePV-generated power actually generated by the photovoltaic device 911 tothe operation planning device 910.

A server 909 is a device which transmits the current amount of solarradiation in the consumer's residence and a predicted future amount ofsolar radiation via the Internet. According to the first embodiment, theserver 909 transmits via the Internet an amount of solar radiationmeasured in the area of the consumer's residence at a predetermined timeinterval.

Moreover, the server 909 calculates a predicted value of an amount ofsolar radiation for each hour for 24 hours from the start of the day at00:00 using the weather forecast for the day and a history of pastamounts of solar radiation measured in the area of the consumer'sresidence, and transmits the predicted values via the Internet once aday at 00:00.

The energy supplier 908 supplies purchased power at the demand of thepower distribution device 905 installed in the consumer's residence.Additionally, when reverse power is input into the power distributiondevice 905, the energy supplier 908 transmits that power via the powergrid to other consumer residences.

The first electric load 906 is an electric load inside the residence ofa consumer, and refers to appliances such as televisions, airconditioners, refrigerators, washing machines, or lights which operateby using power supplied from the power distribution device 905.Furthermore, the sum total of the power used by these appliances isdefined herein as load power.

Moreover, as shown in FIG. 4, with the heat pump hot water supply andheating system 9000 according to the first embodiment, the consumer(user) can switch between hot water supply and heating, for example, byusing a remote control 1101. As shown in FIG. 5, the remote control 1101is equipped with functions to set the heat generated by the heat pump901 to be used for heating (“heating”) or for hot water supply (“hotwater”), and to turn the heat pump 901 off (“off”). When the user setsthe operation mode to any one of these settings, the remote control 1101outputs the selected operation mode to a hot water supply and heatingcontrol device 1001. The user can also set the hot water supplytemperature and the heating temperature with the remote control 1101.When the operation mode is set to “heating”, the temperature of thewater (hot water) to be put in the heating circuit 904 a (to bedescribed later) is set to be the heating temperature setting input bythe user. On the other hand, when the operation mode is set to “hotwater”, the temperature inside a hot water supply tank 903 a (to bedescribed later) is set to be the hot water supply temperature settinginput by the user.

FIG. 3 is a block diagram explaining the details of the heat pump hotwater supply and heating device 900. The heat pump hot water supply andheating device 900 mainly includes the hot water supply and heatingcontrol device 1001, the heat pump 901, the hot water supply device 903,the heating device 904, and a three-way valve 1010 (switching device).The heat pump 901 includes a heat pump unit 901 a and the heat exchanger902. The heat pump hot water supply and heating device 900 operatesusing power received from the power distribution device 905, andtransmits information pertaining to the amount of heating load power tothe power distribution device 905.

The heat pump unit 901 a (not shown in the drawings) includes anevaporator which facilitates heat exchange between outside air and lowtemperature-low pressure liquid refrigerant to generate a lowtemperature-low pressure vaporized refrigerant, a motor-drivencompressor which compresses the low temperature-low pressure vaporizedrefrigerant into a high temperature-high pressure vaporized refrigerant,a condenser which facilitates heat exchange between the hightemperature-high pressure vaporized refrigerant and circulating water(thermal storage medium) to generate a low temperature-high pressureliquid refrigerant, an expansion valve which decreases the pressure ofthe low temperature-high pressure vaporized refrigerant to generate alow temperature-low pressure liquid refrigerant, and a fan to acceleratethe heat conversion between the refrigerant in the evaporator and theoutside air, for example.

The hot water supply tank 903 a stores heat supplied by the hot watersupply load. A hot water supply heater 903 h is located inside the hotwater supply tank 903 a and heats the water therein. The heating circuit904 a is a channel of the heating apparatus for the hot water suppliedby the heating load. The heat exchanger 902 facilitates heat exchangebetween the refrigerant heated by the heat pump unit 901 a and thedownstream water cycle filled with water. The three-way valve 1010 is aswitching device for controlling the channel so the water heated by theheat exchanger 902 flows to one of the hot water supply tank 903 a andthe heating circuit 904 a.

According to the first embodiment, the refrigerant used in the heat pump901 is 410 A refrigerant. As a result of a property of this refrigerant,the temperature at the exit the water cycle side of the heat exchanger902 peaks at 55° C., so the upper temperature limit of the heatingtemperature setting is set to 55° C.

The hot water supply tank 903 a is equipped with an internal heatexchanger coil. This heat exchanger coil is expressed as the dashed lineinside the hot water supply tank 903 a in FIG. 3. When the three-wayvalve 1010 is set to the channel for the hot water supply tank 903 a,the water heated by the heat exchanger 902 flows through the heatexchanger coil and heats the water inside the hot water supply tank 903a. Because the temperature at the exit of the water cycle side of theheat exchanger 902 peaks at 55° C., when the temperature of the hotwater supply tank 903 a is 50° C. or higher, heat exchange via the eachexchange coil is practically nonexistent.

For this reason, when the temperature of the water inside the hot watersupply tank 903 a is heated to 50° C. or higher, the water is heated bysupplying electricity to the hot water supply heater 903 h. Here, thecapacity of the hot water supply tank 903 a is 200 L, the heatingcapacity of the hot water supply heater 903 h is 3 kW, and the uppertemperature limit of the hot water supply temperature setting is 80° C.

In other words, the heat pump unit 901 a can heat the water inside thehot water supply tank 903 a to around 50° C. (the first temperature),and the hot water supply heater 903 h can heat the water inside the hotwater supply tank 903 a beyond 50° C. (the second temperature). It is tobe noted that while water was given as an example of the thermal storagemedium stored in the hot water supply tank 903 a in the firstembodiment, the thermal storage medium is not limited to this example.Any type of thermal storage medium which changes in temperature inresponse to an amount of stored heat can be used.

The hot water supply and heating control device 1001 is a device which,based on set information, controls the entirety of the heat pump hotwater supply and heating device 900 system. As shown in FIG. 4, the hotwater supply and heating control device 1001 obtains operationinformation from the remote control 1101 and the operation planningdevice 910.

The hot water supply and heating control device 1001 obtains theoperation mode, the heating temperature setting, and the hot watersupply temperature setting from the remote control 1101 as operationinformation. The hot water supply and heating control device 1001obtains the priority operation mode and the priority hot water supplytemperature setting from the operation planning device 910 as operationinformation. The priority operation mode has priority over the operationmode obtained from the remote control 1101. Similarly, the priority hotwater supply temperature setting has priority over the hot water supplytemperature setting obtained from the remote control 1101. In otherwords, even if the hot water supply and heating control device 1001obtains the operation mode from the remote control 1101, the priorityoperation mode from the operation planning device 910 is given prioritywhen obtained.

As shown in FIG. 4, the hot water supply and heating control device 1001transmits the amount of hot water supply heat and temperatureinformation for the hot water supply tank to the operation planningdevice 910. The operation planning device 910 receives informationpertaining to the amount of load power, the amount of heating loadpower, and the amount of PV-generated power from the power distributiondevice 905. The operation planning device 910 is also set up to receiveinformation pertaining to the amount of solar radiation and thepredicted amount of solar radiation via the Internet.

When the operation mode is set to “heating”, the hot water supply andheating control device 1001 switches the three-way valve 1010 to theheating circuit 904 a channel, and when the operation mode is set to“hot water”, the hot water supply and heating control device 1101switches the three-way valve 1010 to the hot water supply tank 903 achannel. When the operation mode is set to “stop”, the three-way valve1010 is left unchanged.

Moreover, when the operation mode is set to “heating”, the hot watersupply and heating control device 1001 switches on the heat pump unit901 a and brings the exit temperature of the heat exchanger 902 to theheating temperature setting by adjusting the number of rotations of thecompressor and the diameter, for example, of the expansion valve in theheat pump unit 901 a.

Moreover, when the temperature of the hot water supply tank 903 a drops5° C. or more below the hot water supply temperature setting (hot watersupply temperature setting −5° C. or more), the water inside the hotwater supply tank 903 a is heated by supplying electricity to the hotwater supply heater 903 h. Once the temperature of the hot water supplytank 903 a reaches the hot water supply temperature setting, electricityto the hot water supply heater 903 h is shut off.

Moreover, when the operation mode is set to “hot water” and thetemperature inside the hot water supply tank 903 a is 50° C. or belowand 5° C. or more below the hot water supply temperature setting (hotwater supply temperature setting −5° C. or more), the hot water supplyand heating control device 1001 switches the three-way valve 1010 to thehot water supply tank 903 a channel and controls the heat pump 901 tobring the exit temperature of the heat exchanger 902 to 55° C. This isbecause, as previously stated, when the temperature inside the hot watersupply tank 903 a is 50° C. or higher, heat exchange (heating) via thehot water supply tank 903 a is practically nonexistent.

Moreover, when the temperature of the hot water supply tank 903 a is 50°C. or higher and 5° C. or more below the hot water supply temperaturesetting (hot water supply temperature setting −5° C. or more), the waterinside the hot water supply tank 903 a is heated by supplyingelectricity to the hot water supply heater 903 h. Once the temperatureof the hot water supply tank 903 a reaches the hot water supplytemperature setting, electricity to the hot water supply heater 903 h isshut off.

Moreover, when the hot water supply and heating control device 1001obtains the priority operation mode and the priority hot water supplytemperature setting from the operation planning device 910, thesesettings have priority over the operation mode and hot water supplytemperature setting settings input by the user with the remote control1101. Therefore, the hot water supply and heating control device 1001uses the priority operation mode obtained from the operation planningdevice 910 for the operation mode, and the priority hot water supplytemperature setting obtained from the operation planning device 910 forthe hot water supply temperature setting, and operates accordingly.

As shown in FIG. 1, the operation planning device 910 designs anoperation plan for the heat pump hot water supply and heating device 900which reduces the amount of reverse power and controls operationthereof. Next, details with respect to the configuration of theoperation planning device 910 will be described with reference to FIG.6. As shown in FIG. 6, the operation planning device 910 includes astorage means 301, a load prediction means 302, an operation planningmeans 303, and an operation control means 304.

The storage means 301 stores the amount of load power consumed per hourby the first electric load 906, the amount of heating load powerconsumed per hour by the heat pump hot water supply and heating device900 in order to generate heat to be consumed by the heating device 904,the amount of hot water supply heat consumed per hour by the hot watersupply device 903, the amount of PV-generated power generated per hourby the photovoltaic device 911, and the amount of solar radiation perhour which is a current value of an amount of solar radiation.

Any means of storage capable of recording data may be used as thestorage means 301, such as dynamic random access memory (DRAM),synchronous dynamic random access memory (SDRAM), flash memory, orferrodielectric memory.

The load prediction means 302 calculates the predicted amount of loadpower to be consumed per hour by the first electric load 906, thepredicted amount of heating load power to be consumed per hour by theheat pump hot water supply and heating device 900 in order to generateheat to be consumed by the heating device 904, the predicted amount ofhot water supply heat to be consumed per hour by the hot water supplydevice 903, and the predicted amount of PV-generated power to begenerated per hour by the photovoltaic device 911.

The operation planning means 303 designs an operation plan for the heatpump hot water supply and heating device 900 which minimizes the amountof reverse power, and calculates the control parameters which controlthe operation of the heat pump hot water supply and heating device 900.Lastly, the operation control means 304 controls the operation of theheat pump hot water supply and heating device 900 based on controlparameters.

(Storage Means)

First, the storage means 301 stores values corresponding to theconsumer's amount of load power, amount of heating load power, amount ofhot water supply heat, amount of PV-generated power, and amount of solarradiation. More specifically, as shown in the history table in FIG. 7,the storage means 301 stores, for a predetermined period of time only(four weeks in the example shown in FIG. 7), a value of load powermeasured per hour (amount of load power) in a load power history, avalue of heating load power measured per hour (amount of heating loadpower) in a heating load power history, a value of an amount of hotwater supply heat measured per hour in a hot water supply heat history,a value of PV-generated power measured per hour (amount of PV-generatedpower) in a PV-generated power history, and a value of an amount ofsolar radiation measured per hour in a solar radiation history. Historyinformation (load power, heating load power, amount of hot water supplyheat, PV-generated power, and amount of solar radiation) for each day ofthe week for four weeks is stored in this history table. Information foreach hour of each day is further stored in more detail. The numbers 0,1, 2, and so on represent the hours of the day 00:00, 01:00, 02:00, andso on. Moreover, the history information for the hours of the day isaccumulated information. The load power history for the hour 0 is theaccumulated amount of load power for the hour 00:00.

The load prediction means 302 is set up to be able to obtain desiredinformation from the storage means 301, such as the amount of load powerfor 15:00 to 16:00 from the previous week, or the amount of hot watersupply heat for 18:00 to 22:00 from two weeks ago, for example. The sameis also true for the amount of load power, the PV-generated power, andthe amount of solar radiation as well.

The operation planning device 910 obtains the amount of load power andthe amount of PV-generated power from the power distribution device 905,the heating load power and the amount of hot water supply heat from theheat pump hot water supply and heating device 900, and the amount ofsolar radiation from the offsite server 909 via the Internet. Here, theamount of solar radiation is an amount of solar radiation for theconsumer's area of residence.

The amount of hot water supply heat refers to an amount of heat consumed(radiated) per hour by the hot water supply device 903. The amount ofheating load power refers to an amount of power consumed per hour by theheat pump hot water supply and heating device 900 in order to generateheat to be consumed by the heating device 904. This amount of power isthe total amount of power required to operate the heat pump 901 and thewater pump, for example. The amount of load power refers to an amount ofpower consumed per hour by the first electric load 906. The amount ofPV-generated power refers to an amount of power generated per hour bythe photovoltaic device. The amount of solar radiation refers to acurrent amount of solar radiation per unit area for the consumerobtained from the server 909.

Moreover, the operation planning device 910 accumulates each piece ofinformation in one hour units obtained throughout the previous day andstores values for the previous four weeks (28 days) in the storage means301.

(Load Prediction Means)

The load prediction means 302 calculates a predicted value of the amountof load power to be consumed per hour by the first electric load 906(predicted amount of load power), a predicted value of the amount ofheating load power to be consumed per hour by the heat pump hot watersupply and heating device 900 in order to generate heat to be consumedby the heating device 904 (amount of load power), a predicted value ofthe amount of hot water supply heat to be consumed per hour by the hotwater supply device 903 (predicted amount of hot water supply heat), anda predicted value of the amount of PV-generated power to be generatedper hour by the photovoltaic device 911 (predicted amount ofPV-generated power).

The load prediction means 302 predicts the amount of load power, theamount of heating load power, and the amount of hot water supply heatfor each time period to be equivalent to the average of the powerconsumption values stored in the storage means 301 measured over fourprevious weeks from a corresponding time period on the same day of theweek. For example, when predicting the amount of load power, the amountof heating load power, and the amount of hot water supply heat from19:00 to 20:00 on a Tuesday, the load prediction means 302 obtainsvalues measured from 19:00 to 20:00 on Tuesday over four previous weeksfrom the storage means 301, and uses the average of those values as thepredicted value.

The load prediction means 302 obtains the predicted amount of solarradiation for each time period for the prediction target day from theserver 909 via the Internet. The load prediction means 302 then, foreach time period, predicts the amount of PV-generated power to beequivalent to, from among previously measured amounts of PV-generatedpower, the amount of PV-generated power during a time period with anamount of solar radiation that is closest to the predicted amount ofsolar radiation. That is, the load prediction means 302 searches thesolar radiation history stored in the storage means 301 for a timeperiod having a value that is the same as or closest to the predictedamount of solar radiation, then obtains the amount of PV-generated powermeasured for that time period from the PV-generated power history, andmakes the obtained amount of PV-generated power the predicted amount ofPV-generated power for the target time period.

The load prediction means 302 performs the prediction process describedabove once a day at 00:00, and calculates a predicted value for eachhour for 24 hours.

(Operation Planning Means)

The operation planning means 303 designs an operation plan for the heatpump hot water supply and heating device 900 which minimizes the amountof reverse power, and calculates the control parameters for the heatpump hot water supply and heating device 900.

According to the first embodiment, the operation planning means 303obtains the predicted amount of load power, the predicted amount ofheating load power, the predicted amount of hot water supply heat, andthe predicted amount of PV-generated power from the load predictionmeans 302. The operation planning means 303 further obtains from theheat pump hot water supply and heating device 900 the hot water supplytemperature setting (the current temperature setting) thereof. Theoperation planning means 303 performs an operation plan designingprocess once a day at, for example, 00:00.

First, for each time period (00:00, 01:00 . . . 22:00, 23:00), theoperation planning means 303 calculates the predicted amount of reversepower by subtracting the predicted amount of load power and thepredicted amount of heating load power from the corresponding predictedamount of PV-generated power. The lower limit of the predicted amount ofreverse power is zero. In the evening, the predicted amount ofPV-generated power becomes zero, and reverse power is not generated. Thetime when the predicted amount of reverse power for each time periodfirst becomes zero counting backwards from 24:00, in other words, thetime at which the predicted amount of reverse power changes from apositive value to a non-positive value, is defined as the reverse flowstandby start time.

Next, FIG. 8 will be explained in detail. The horizontal axis representstime, and the vertical axis represents amount of power. The blackdiamonds represent the predicted amount of load power, the X's representthe predicted amount of heating load power, the shaded squares representthe predicted amount of PV-generated power, and the black trianglesrepresent the predicted amount of reverse power. The predicted amount ofreverse power (black triangle) is yielded by subtracting the predictedamount of load power and the predicted amount of heating load power fromthe predicted amount of PV-generated power. Each amount of power for agiven time is represented as an accumulated value. For example, if thetime is 12:00, the amount of power shown for 12:00 (from 12:00 to 13:00)is an accumulated amount.

As shown in FIG. 8, the reverse flow standby start time, the time atwhich the predicted amount of reverse power becomes zero, is 17:00. Whenthe amount of heat obtained by accumulating each predicted amount of hotwater supply heat (amount of heat to be radiated in reverse flowstandby) from the reverse flow standby start time of 17:00 to 24:00(reverse flow standby time period) is stored in the hot water supplytank 903 a by the reverse flow standby start time in advance using thereverse power, heating the hot water supply tank 903 a after the reverseflow standby start time becomes unnecessary, thereby avoidingconsumption of extra power. The predicted amount of hot water supplyheat can be calculated, for example, by obtaining the amounts of hotwater supply heat from the same day of the week measured between 17:00and 24:00 over four weeks from the hot water supply heat history andaveraging the amounts.

The temperature calculated by dividing this accumulated predicted amountof hot water supply heat for the time period between 17:00 and 24:00 bythe capacity of the hot water supply tank 903 a (for example 200 L) isset as the heat storage target temperature. In short, the heat pump 901to generates heat so that the hot water supply tank 903 a can reach thisheat storage target temperature. In other words, the heat pump 901 stopsgenerating heat when the hot water supply tank 903 a reaches thistemperature.

There are cases when an upper temperature limit is set for the heatstored in the hot water supply tank 903 a. If the heat storage targettemperature exceeds this upper temperature limit, the heat storagetarget temperature setting is replaced by the upper temperature limit.Here, the upper temperature limit for the heat stored in the hot watersupply tank 903 a is set to 80° C.

The amount of heat to be stored in the hot water supply tank 903 a inreverse flow can be calculated from the heat storage target temperatureand the current temperature setting of the heat pump hot water supplyand heating device 900 (hot water supply temperature setting). Theamount of heat to be generated in reverse flow, which is the amount ofheat generated by the heat pump 901 during the reverse flow of power andstored in the hot water supply tank 903 a, is calculated using Equation1 described below. This amount of heat to be generated in reverse flowis equivalent to the amount of heat to be radiated in reverse flowstandby which is radiated by the hot water supply device 903 in thereverse flow standby time period (from 17:00 to 24:00).amount of heat to be generated in reverse flow=(heat storage targettemperature−hot water supply temperature setting)×hot water supply tankcapacity  (Equation 1)

Next, the operation planning means 303 calculates the reverse flow heatgeneration time, which is the amount of time required for the heat pump901 to generate the amount of heat to be generated in reverse flow,using Equation 2 described below.

Also, the HP average capacity is 9 kW. The HP average capacity is anaverage heating capacity of the heat pump 901, and is a value that issaved in advance. The scaling ratio for converting from amount of heat(kcal) to power (kW) is 0.86.reverse flow heat generation time=(amount of heat to be generated inreverse flow/0.86/1000)/HP average capacity  (Equation 2)

Next, as shown in FIG. 9, the operation planning means 303 calculatesthe predicted amount of reverse power for each time period. FIG. 9expresses the values from the graph in FIG. 8 in table form. Thepredicted amount of reverse power for any given time period is expressedas an accumulated value of that time period. For example, in the case ofthe time 00:00, as previously stated, the value expressed is anaccumulated value of the predicted reverse power between 00:00 and01:00. Also, priority in FIG. 9 is assigned in descending order bypredicted amount of reverse power.

Next, the operation planning means 303 determines the operation periodwhich is the time period the heat pump 901 operates, and the reversepower threshold value which is for determining when the heat pump 901actually begins generating heat. The operation period includes the timeperiod having the largest predicted amount of reverse power.Specifically, the operation planning means 303 selects, as the operationperiod, a number of one or more time periods in descending order ofamount of reverse power (that is, in descending order of priority) untilthe selection exceeds the reverse flow heat generation time. The reversepower threshold value is equal to the value of the operation period withthe smallest amount of reverse power.

For example, when the reverse flow heat generation time is calculated tobe 0.5 hours, the time period in FIG. 9 with the highest priority(12:00) is selected as the operation period. In this case, the heatstorage start time reverse power is 1.68 kW. However, when the reverseflow heat generation time is calculated to be 3.2 hours, the time isrounded up and time periods totaling 4 hours are acquired. In short, theoperation period becomes the time period from 10:00 through 13:00, or inother words, the four time periods with the priorities 1 through 4. Inthis case, the heat storage start time reverse power is 1.00 kW.

The operation planning means 303 then transmits the determined heatstorage target temperature, the operation period, and the reverse powerthreshold value as control parameters to the operation control means304.

As shown in FIG. 4, the heat pump hot water supply and heating system9000 according to the first embodiment is configured to be able toswitch channels between the hot water supply tank 903 a and the heatingcircuit 904 a via the three-way valve 1010 after the heat exchanger 902facilitates heat exchange. Moreover, because the heat exchanger 902 canonly heat the hot water supply tank 903 a to approximately 50° C., thehot water supply tank 903 a is provided with the hot water supply heater903 h therein in order to heat itself beyond 50° C.

In other words, with respect to the amount of heat corresponding to theamount of heat to be radiated in reverse flow standby, the operationplanning device 910 designs an operation plan to cause the heat pumpunit 901 a to generate an amount of heat until the temperature of thewater inside the hot water supply tank 903 a reaches 50° C., and causethe hot water supply heater 903 h to generate an amount of heat afterthe temperature of the water reaches 50° C. The calculation method fordetermining the amount of heat needed in reverse flow is describedhereinafter.

(1) When the hot water supply temperature setting (the currenttemperature setting for the hot water supply tank 903 a) is below 50°C.:

When the hot water supply temperature setting is below 50° C., theoperation planning means 303 uses Equation 3 below to calculate thereverse flow HP generated heat, which is an amount of heat to begenerated by the heat pump 901 in reverse flow, and Equation 4 below tocalculate the reverse flow heater generated heat, which is an amount ofheat generated by the hot water supply heater 903 h in reverse flow.reverse flow HP generated heat=(50−hot water supply temperaturesetting)×hot water supply tank capacity  (Equation 3)reverse flow heater generated heat=(heat storage targettemperature−50)×hot water supply tank capacity  (Equation 4)

(2) When the hot water supply temperature setting (the currenttemperature setting for the hot water supply tank 903 a) is 50° C. orhigher:

When the hot water supply temperature setting is 50° C. or higher, theoperation planning device 910 uses Equation 5 below to calculate thereverse flow heater generated heat, which is an amount of heat to begenerated by the hot water supply heater 903 h.reverse flow heater generated heat=(heat storage target temperature−hotwater supply temperature setting)×hot water supply tankcapacity  (Equation 5)

Next, the operation planning means 303 uses Equation 6 below tocalculate the reverse flow HP heat generation time t(HP), which is theamount of time required for the heat pump 901 to generate the reverseflow HP generated heat, and Equation 7 below to calculate the reverseflow heater heat generation time t(HT), which is the amount of timerequired for the hot water supply heater 903 h to generate the reverseflow heater generated heat.

It is to be noted that the HP average capacity is 9 kW. The HP averagecapacity is an average heating capacity of the heat pump 901, and is avalue that is saved in advance. Moreover, the heating capacity of theheater, which is the average heating capacity of the hot water supplyheater 903 h, is 3 kW. The scaling ratio for converting from amount ofheat (kcal) to power (kW) is 0.86.t(HP)=(reverse flow HP generated heat/0.86/1000)/HP averagecapacity  (Equation 6)t(ht)=(reverse flow heater generated heat/0.86/1000)/heating capacity ofthe heater  (Equation 7)

Next, the operation planning means 303 calculates the reverse flow heatgeneration time by adding the reverse flow HP heat generation time andthe reverse flow heater heat generation time (t(HP)+t(HT)). Theoperation planning means 303 designs the operation plan for the heatpump 901 from the calculated reverse flow heat generation time.Moreover, heating via the hot water supply heater 903 h is donefollowing the operation of the heat pump 901, but the operation plan isdesigned so operation of the hot water supply heater 903 h is alsostopped before the reverse flow standby start time.

(1) When the reverse power is below the reverse power threshold value:

Both priority operation mode and priority hot water supply temperaturesettings are obtained to be “absent”. In this case, the heat pump hotwater supply and heating system 9000 operates according to the settingsreceived from the remote control 1101.

(2) When the reverse power is the same as or higher than the reversepower threshold value:

(i) When the temperature of the hot water supply tank is below 50° C.:

The priority operation mode is obtained to be “hot water”, and thepriority hot water supply temperature setting is obtained to be “heatstorage target temperature”. In this case, because the temperature canbe reached with just the heating capacity of the heat pump 901, the heatpump hot water supply and heating device 900 sets the operation mode to“hot water” and uses the heat pump 901 to heat the water inside the hotwater supply tank 903 a.

(ii) When the temperature of the hot water supply tank is 50° C. orhigher:

The priority operation mode is obtained to be “absent”, and the priorityhot water supply temperature setting is obtained to be “heat storagetarget temperature”. In this case, because the temperature exceeds theheating capacity of the heat pump 901 (50° C.), the heat pump hot watersupply and heating device 900 leaves the operation mode as received fromthe remote control 1101, and uses the hot water supply heater 903 h toheat the water inside the hot water supply tank 903 a. There is no otheroption but to use the hot water supply heater 903 h to heat the waterinside the hot water supply tank, even if the setting on the user remotecontrol is “heating” or “hot water”.

(Operation Control Means)

The operation control means 304 controls the operation of the heat pumphot water supply and heating device 900 based on the control parametersgenerated by the operation planning means 303. The operation controlmeans 304 obtains the reverse power threshold value, the operationperiod, and the heat storage target temperature for the hot water supplytank 903 a from the operation planning means 303, obtains the currentamount of load power and the current amount of PV-generated power fromthe power distribution device 905, and obtains the current heating loadpower and the current temperature of the hot water supply tank 903 a(hot water supply tank temperature) from the heat pump hot water supplyand heating device 900. The operation control means 304 calculates thereverse power by subtracting the load power and the heating load powerfrom the PV-generated power. These processes are performed, for example,every minute.

Even if it is mid-operation period, operation of the heat pump 901 willnot be started if the calculated current reverse power is short of thereverse power threshold value. Once the calculated current reverse powerreaches the reverse power threshold value, operation of the heat pump901 will be started. Moreover, because the operation control means 304obtains the temperature of the hot water supply tank 903 a in one minuteintervals, operation of the heat pump 901 is stopped when the hot watersupply tank 903 a reaches the heat storage target temperature.

By operating the heat pump 901 according to the operation plan designedby the operation planning device 910 in a time period with the peakamount of reverse power, the reverse power for that time period can bereduced (peak-cut). As a result, the effect power flowing in reverse hason the power grid can be effectively reduced. Moreover, the amount ofheat to be radiated in reverse flow standby predicted to be needed afterthe reverse flow standby start time (17:00 in FIG. 8) can be providedwith natural energy. As a result, energy can be saved as there is noneed to purchase power from the energy supplier 908.

Operation of the First Embodiment

Hereinafter, an exemplary operation according to the first embodiment ofthe heat pump hot water supply and heating system is described. Thedescription will be given on the premise that the current time is 00:00,and the heat pump hot water supply and heating system has been operatingfor 4 weeks (28 days) or more. The hot water supply temperature settingis set to 45° C. Also, the temperature inside the hot water supply tank903 a at 00:00 is an even 50° C.

(Update Process of the Operation Planning Device at 00:00)

FIG. 10 is a flowchart of an operation planning process performed by theoperation planning device 910 every day at 00:00. First, when thecurrent time becomes 00:00, the operation planning device 910 begins theonce daily operation planning process (S601).

Next, the operation planning device 910 updates the storage means 301(S602). The amount of load power, the amount of heating load power, theamount of hot water supply heat, the amount of PV-generated power, andthe amount of solar radiation for the past 24 hours are newly added tothe storage means 301 as hourly accumulated values.

Moreover, because the heat pump hot water supply and heating system hasbeen operating over the past 28 days or more, the load power history,the heating load power history, the hot water supply heat history, thePV-generated power history, and the solar radiation history for 28 daysare stored in the storage means 301 in one hour units. Each history isupdated by discarding the oldest days worth of data from each history,then adding the most recent days worth of data to each history.

Next, the operation planning device 910 performs a prediction processusing the load prediction means 302 (S603). FIG. 11 is a flowchart ofthe prediction process performed by the load prediction means 302(S603). First, the load prediction means 302 begins the predictionprocess (S701).

Next, the load prediction means 302 obtains data necessary for loadprediction (S702). The load prediction means 302 obtains the predictedamount of solar radiation from the server 909 as well as necessary datafrom the load power history, the heating load power history, the hotwater supply heat history, the PV-generated power history, and the solarradiation history for the past 28 days stored in the storage means 301.

Next, the load prediction means 302 calculates the predicted amount ofload power for each hour (S703). As previously stated, the loadprediction means 302 calculates the predicted amount of load power foreach time period for a 24 hour period by obtaining, from the load powerhistory, four amounts of load power from the same time period and day ofthe week as the prediction target day, and setting the predicted valueas the average of the four obtained amounts.

Next, the load prediction means 302 calculates the predicted amount ofheating load power for each hour (S704). As previously stated, the loadprediction means 302 calculates the predicted amount of heating loadpower for each time period for a 24 hour period by obtaining, from theheating load power history, four amounts of heating load power from thesame time period and day of the week as the prediction target day, andsetting the predicted value as the average of the four obtained amounts.

Next, the load prediction means 302 calculates the predicted amount ofhot water supply heat (S705). As previously stated, the load predictionmeans 302 calculates the predicted amount of hot water supply heat foreach time period for a 24 hour period by obtaining, from the hot watersupply heat history, four amounts of hot water supply heat from the sametime and day of the week as the prediction target day, and setting thepredicted value as the average of the four obtained amounts.

Next, the load prediction means 302 calculates the predicted amount ofPV-generated power (S706). As previously stated, the load predictionmeans 302 searches the solar radiation history for a time period havinga value that is the same as or closest to the per hour predicted amountof solar radiation. Then, the load prediction means 302 calculates thepredicted amount of PV-generated power for each time period a 24 hourperiod by obtaining, from the PV-generated power history, an amount ofPV-generated power corresponding to the found time period, and settingthat value as the predicted value.

This completes the load prediction process (S603) of the load predictionmeans 302 (S707).

(Operation Planning Means)

Next, the operation planning device 910 performs a control parametercalculation process using the operation planning means 303 (S604). FIG.12 is a flowchart of the control parameter calculation process performedby the operation planning means 303 (S604). First, the operationplanning means 303 begins the control parameter calculation process(S801).

Next, the operation planning means 303 obtains data necessary for thecontrol parameters (S802). The operation planning means 303 obtains thehot water supply temperature setting from the heat pump hot water supplyand heating device 900, and obtains the predicted amount of load power,the amount of heating load power, the predicted amount of hot watersupply heat, and the predicted amount of PV-generated power from theload prediction means 302.

Next, the operation planning means 303 calculates the reverse flowstandby start time (S803). As previously stated, the operation planningmeans 303 calculates the predicted amount of reverse power, which is avalue with a lower limit of zero, by subtracting the predicted amount ofload power and the predicted amount of heating load power from thepredicted amount of PV-generated power.

As shown in the example in FIG. 8, because the predicted amount ofPV-generated power becomes zero from the evening on and reverse power isnot generated, the time when the value of the predicted amount ofreverse power for each time period first becomes zero counting backwardsfrom 24:00 is set as the reverse flow standby start time. For example,the reverse flow standby start time in the example in FIG. 8 is 17:00.

Next, the operation planning means 303 calculates the heat storagetarget temperature (S804). As previously stated, the operation planningmeans 303 sets the heat storage target temperature as the lower of theupper temperature limit of the hot water supply temperature setting (80°C.) and the temperature calculated by dividing the amount of heatobtained through accumulating the predicted amount of hot water supplyheat between the reverse flow standby start time and 24:00 by thecapacity of the hot water supply tank 903 a (200 L).

For example, when the amount of heat obtained by accumulating thepredicted amount of hot water supply heat between the reverse flowstandby start time and 24:00 is 15000 kcal, the temperature calculatedby dividing this by the 200 L tank capacity is 75° C. Thus, because 75°C. is lower than the upper temperature limit of the hot water supplytemperature setting (80° C.), the heat storage target temperature willbe set to 75° C.

Next, the operation planning means 303 calculates the amount of heat tobe generated in reverse flow (S805). The operation planning means 303calculates the amount of heat to be generated in reverse flow which isthe amount of heat to be generated by the heat pump 901. This amount ofheat to be generated in reverse flow is equivalent to the amount of heatto be radiated in reverse flow standby.

For example, using Equation 1, when the heat storage target temperatureof the hot water supply tank 903 a is 75° C. and the hot water supplytemperature setting is 45° C., the amount of heat to be generated inreverse flow is calculated to be 6000 kcal.

Next, the operation planning means 303 calculates the reverse flow heatgeneration time (S806). As previously described, the operation planningmeans 303 uses Equation 2 to calculate the reverse flow heat generationtime, which is the amount of time required for the heat pump 901 togenerate the amount of heat to be generated in reverse flow. Forexample, using Equation 2, the reverse flow HP heat generation time iscalculated to be 0.78 hours with respect to the value calculated above(6000 kcal).

Next, the operation planning means 303 calculates the operation periodand the reverse power threshold value (S807). As previously described,the operation planning means 303 selects, as the operation period, anumber of one or more time periods in descending order of predictedamount of reverse power until the selection exceeds the reverse flowheat generation time. Moreover, the predicted amount of reverse poweramong the one or more selected time periods included in the operationperiod with the lowest value is set as the reverse power thresholdvalue. For example, if the result of arranging the predicted amount ofreverse power in descending order is like the example shown in FIG. 9,when the calculated reverse flow heat generation time is 0.78 hours,time period 12:00 having a reverse power threshold value of 1.68 kW isselected as the operation period.

With the above processes, the operation planning means 303 completes(S808) the control parameter calculation process (S604), and theoperation planning device 910 completes (S605) the operation planningprocess.

The operation planning device 910 performs an operation control processof the heat pump hot water supply and heating device 900 using theoperation control means 304 in one minute intervals during the timeperiod from the completion of the operation planning process until 00:00of the next day.

After the completion of the operation planning process, the operationcontrol means 304 obtains the heat storage target temperature, theoperation period, and the reverse power threshold value from theoperation planning means 303, and obtains the load power and thePV-generated power in one minute intervals from the power distributiondevice 905, and obtains the heating load power and the temperature ofthe hot water supply tank 903 a in one minute intervals from the heatpump hot water supply and heating device 900. Each time information isobtained per minute, the operation control means 304 calculates thereverse power by subtracting the load power and the heating load powerfrom the PV-generated power.

Even if it is mid-operation period, operation of the heat pump 901 willnot be started if the calculated current reverse power is short of thereverse power threshold value. Once the calculated current reverse powerreaches the reverse power threshold value, operation of the heat pump901 will be started. Moreover, because the operation control means 304obtains the temperature of the hot water supply tank 903 a in one minuteintervals, operation of the heat pump 901 is stopped when the hot watersupply tank 903 a reaches the heat storage target temperature.

Moreover, the operation planning device 910 performs a process in whicheach of the various pieces of information is stored in predeterminedtime intervals in the storage means 301 during the time period from thecompletion of the operation planning process until 00:00 of the nextday. The amount of hot water supply heat and the amount of heating loadpower obtained from the heat pump hot water supply and heating device900, the amount of load power obtained from the power distributiondevice 905, the amount of PV-generated power obtained from thephotovoltaic device 911, and the amount of solar radiation obtained fromthe server 909 are stored in the storage means 301.

The obtained respective values are accumulated hourly, and when the timechanges according to the time information stored internally, theaccumulated values for the past hour coupled with the time are stored inthe storage means 301, whereby the accumulated value is reset to 0.

According to the first embodiment, using the operation planning means303, the operation planning device 910 stores an amount of heat in thehot water supply tank 903 a at the reverse flow standby start time thatcorresponds to the predicted amount of hot water supply heat between thereverse flow standby start time and 24:00 based on the predictioninformation from the load prediction means 302.

On a day having a low predicted amount of hot water supply heat, forinstance, radiant heat loss occurs when the hot water supply tank 903 ais heated to the set upper temperature limit (80° C.) in order to use upall of the reverse power. However, according to the first embodiment,because a necessary amount of heat is predicted, heat which would go towaste is not generated, and a low-energy performance characteristic ismaintained.

Following the configuration according to the present invention asoutlined above allows for a low-energy performance characteristic to bemaintained whereby the amount of reverse power generated is decreased inthe system including the photovoltaic device 911 and the heat pump hotwater supply and heating device 900.

Specific Example

Hereinafter, an operation of the heat pump hot water supply and heatingsystem 9000 according to the first embodiment is described. Thedescription will be given on the premise that the current time is 00:00,and the heat pump hot water supply and heating system 9000 has beenoperating for 4 weeks (28 days) or more. Moreover, on the remote control1101, the operation mode information is “heating”, the heatingtemperature setting is “50° C.”, and the hot water supply temperaturesetting is “45° C.”. Also, the temperature inside the hot water supplytank 903 a at 00:00 is an even 50° C.

First, when the hot water supply temperature setting is below 50° C.,the operation planning means 303 uses Equation 3 to calculate thereverse flow HP generated heat, which is the amount of heat to begenerated by the heat pump 901, and Equation 4 to calculate the reverseflow heater generated heat, which is the amount of heat to be generatedby the hot water supply heater 903 h.

For example, when the heat storage target temperature is 75° C. and thehot water supply temperature setting is 45° C., because the hot watersupply temperature setting is below 50° C., Equation 3 and Equation 4are calculated to get a reverse flow HP generated heat of 1000 kcal anda reverse flow heater generated heat of 5000 kcal. For both Equation 3and Equation 4, a storage tank capacity of 200 L was used.

Next, the operation planning means 303 calculates the reverse flowheating time. The operation planning means 303, as previously stated,uses Equation 6 to calculate the reverse flow HP heat generation time,which is the amount of time required for the heat pump 901 to generatethe reverse flow HP generated heat, and Equation 7 to calculate thereverse flow heater heat generation time, which is the amount of timerequired for the hot water supply heater 903 h to generate the reverseflow heater generated heat.

For example, with respect to the above calculated reverse flow HPgenerated heat and the reverse flow heater generated heat, the reverseflow HP heat generation time t(HP)=0.13 hr, and the reverse flow heaterheat generation time t(HT)=1.94 hr.

Next, the operation planning means 303 calculates the reverse flowheating time by adding the reverse flow HP heat generation time and thereverse flow heater heat generation time (t(HP)+t(HT)). For example,with respect to the above calculated t(HP) and t(HT), the reverse flowheating time is calculated to be 2.07 hr.

In this case, with respect to the figures in FIG. 9, the operationperiod is set to the time period from 11:00 through 13:00, or in otherwords, the time periods with the priorities 1 through 3, whereby theselected operation period with the lowest predicted amount of reversepower is set as the reverse power threshold value (1.38 kW).

Hereinafter, an operation of the heat pump hot water supply and heatingdevice 900 according to the first embodiment is described. FIG. 13 is aflow chart showing an operation of the heat pump hot water supply andheating device 900.

First, the hot water supply and heating control device 1001 monitors thereverse power and starts the operation of the heat pump hot water supplyand heating device 900 when the reverse power reaches the reverse powerthreshold value (S1601). When the operation is started, if thetemperature of the hot water supply tank (the current temperature of thehot water supply tank 903 a) is 50° C. or above (S1602), heat isgenerated by the hot water supply heater 903 h (S1603), and when thewater inside the hot water supply tank 903 a reaches the heat storagetarget temperature (S1604), the generation of heat via the hot watersupply heater 903 h is stopped (S1605).

In contrast, when the temperature of the hot water supply tank is below50° C. (S1602), heat is first generated by the heat pump unit 901 a. Atthis time, if the heat storage target temperature is below 50° C.(S1606), heat will only be generated by the heat pump unit 901 a(S1609). When the water inside the hot water supply tank 903 a reachesthe heat storage target temperature (S1610), the generation of heat viathe heat pump unit 901 a is stopped (S1611).

However, if the heat storage target temperature is 50° C. or above(S1606), heat is generated by the heat pump unit 901 a until thetemperature of the water inside the hot water supply tank 903 a reaches50° C. (S1607). Furthermore, after the temperature of the water insidethe hot water supply tank 903 a reaches the upper temperature limit of50° C. (S1608), heat is generated by the hot water supply heater 903 huntil the heat storage target temperature is reached (S1603). Once thewater inside the hot water supply tank 903 a reaches the heat storagetarget temperature (S1604), the generation of heat via the hot watersupply heater 903 h is stopped (S1605).

Hereinafter, other examples of an operation of the heat pump hot watersupply and heating device 900 according to the first embodiment isdescribed. FIG. 14 is a flow chart showing an operation of the heat pumphot water supply and heating system 9000 according to the firstembodiment. This flow chart shows a method of controlling the heat pumphot water supply and heating system 9000 at a time in which the storageof heat in the hot water supply tank 903 a is to be started, when theheat pump unit 901 a is already operating in order to supply heat to theheating device 904.

First, the hot water supply and heating control device 1001 monitors thereverse power and starts the operation of the heat pump hot water supplyand heating device 900 when the reverse power reaches the reverse powerthreshold value (S1701). For example, when the heat storage targettemperature is 75° C., if the temperature of the hot water supply tank903 a is already 50° C. or above (YES in S1702), the remaining amount ofheat to be stored is generated by the hot water supply heater 903 h(S1703).

However, if the temperature of the hot water supply tank 903 a is below50° C. (NO in S1702), first it is determined whether or not the heatpump unit 901 a is being used to supply heat to the heating device 904(S1706). If the heat pump unit 901 a is not being used, the heat pumpunit 901 a is operated to generate heat to increase the temperature ofthe water inside the hot water supply tank 903 a. However, if the heatpump unit 901 a is being used to supply heat to the heating device 904,the hot water supply tank 903 a is given priority over the heatingdevice 904, and heat is stored in the hot water supply tank 903 a. Inother words, as is shown in the flow chart, the three-way valve 1010 isswitched from the heating device 904 to the hot water supply tank 903 a(S1707), and the heat pump unit 901 a is operated to store heat in thehot water supply tank 903 a (S1708).

The temperature of the hot water supply tank 903 a is measured in oneminute intervals, and the heat pump unit 901 a is made to continuegenerating heat until the temperature of the hot water supply tank 903 areaches 50° C. When the hot water supply tank 903 a reaches 50° C., asis shown in the flow chart, the hot water supply heater 903 h is usedfor storing the remaining heat (S1703), and when the heat storage targettemperature is reached (S1704), storage of the heat by the hot watersupply heater 903 h is completed (S1705).

Hereinafter, an advantage of the heat pump hot water supply and heatingsystem 9000 according to the first embodiment is described.

The operation planning device 910 according to the first embodimentpredicts the amount of load power, the amount of heating load power, theamount of hot water supply heat, and the amount of PV-generated powerfor each time period for the prediction target day, and designs anoperation plan for heating the hot water supply tank 903 a using reversepower based on the predicted information. The operation planning device910 then selects, as the operation period, a number of one or more timeperiods in descending order of amount of reverse power, and sets theamount of reverse power with the lowest value among the selected timeperiods as the reverse power threshold value.

For example, as described above with respect to the figures in FIG. 9,when the reverse flow heat generation time is 2.07 hr, the operationperiod is the time period from 11:00 through 13:00. Because thepredicted amount of reverse power is for 11:00, 12:00, and 13:00 is 1.44kW, 1.68 kW, and 1.38 kW, respectively, the reverse power thresholdvalue is set to the smallest value among the three of 1.38 kW.

The operation planning device 910 then gives the above determinedcontrol parameters priority over the setting information according tothe remote control 1101, and uses the control parameters to control theheat pump hot water supply and heating device 900.

As a result, an operation can be achieved in which as little reversepower as possible is output to the energy supplier 908, even when thewater inside the hot water supply tank 903 a is heated by the heat pumphot water supply and heating device 900.

FIG. 15 is a comparison of the power consumption required to heat thewater inside the hot water supply tank 903 a when the load predictionmeans 302 is not used for the sake of example.

With results of the present invention in FIG. 15, it is clear that byoperating according to the operation plan using the prediction resultsof the load prediction means, the amount of reverse power is minimized.

Following the configuration according to the present invention asoutlined above allows for a low-energy performance characteristic to bemaintained whereby the amount of reverse power generated is reduced inthe heat pump hot water supply and heating system 9000 including thephotovoltaic device 911.

(Other Configurations)

Hereinbefore, the heat pump hot water supply and heating systemaccording the embodiments of the present invention provided with thepower generation device were described. However, the followingembodiments are also acceptable.

While the photovoltaic device is used as an example of the powergeneration device, a plurality of photovoltaic devices coupled togethermay also be used as the power generation device.

Moreover, the operation planning device is set up outside the hot watersupply and heating device, but the operation planning device may be setup inside the hot water supply and heating device or inside the powerdistribution device. The operation plan function of the operationplanning device may also be a part of the hot water supply device or thepower distribution device instead.

Moreover, the reverse power threshold value is calculated by theoperation planning means and the hot water supply and heating device iscontrolled according to the amount of reverse power using the operationcontrol means, but the hot water supply and heating device may beoperated by setting a timer for a predetermined time period calculatedto minimize reverse power, such as from 11:00 through 13:00.

Moreover, the operation planning device performs the operation planningprocess once a day at 00:00, but the process may be performed more thanone time a day and at an arbitrary time such as 02:00 or 06:00 insteadof 00:00. In this case, the end of the reverse flow standby time period(24:00 in the embodiment examples) is also adjusted accordingly. Inother words, after the completion of the reverse flow standby timeperiod, which is a time period delimited by the reverse flow standbystart time (17:00 in the embodiment) and a predetermined assumed timeradiator unit (the hot water supply device) will stop radiating heat,the operation planning device may design an operation plan for the nextday.

Moreover, the unit time for the load information and predictioninformation used in the processing by the operation planning device isone hour, but an arbitrary unit time, such as 15 minutes or one minute,may be used for the information.

Moreover, an average of past values from the same time and day of weekis used for the prediction values used by the load prediction means, butprediction using a neural network or another technique may also be used.

Hereinbefore, the embodiment of the present invention was described withreference to the drawings, but the present invention is not limited tothe embodiment shown in the drawings. It is acceptable to add variationsto or modify the embodiment depicted in the drawings within the scope ofthe invention or an equal scope.

INDUSTRIAL APPLICABILITY

The operation planning device according to the present invention isuseful in contributing to the stabilization of the power grid when a hotwater supply system or a hot water supply and heating system, forexample, is in operation.

REFERENCE SIGNS LIST

-   301 storage means-   302 load prediction means-   303 operation planning means-   304 operation control means-   900 heat pump hot water supply and heating device-   901 heat pump-   901 a heat pump unit-   902 heat exchanger-   903 hot water supply device-   903 a hot water supply tank-   903 h hot water supply heater-   904 heating device-   904 a heating circuit-   905 power distribution device-   906 first electric load-   907 power meter-   908 energy supplier-   909 server-   910 operation planning device-   911 photovoltaic device-   1001 hot water supply and heating control device-   1010 three-way valve-   1101 remote control-   9000 heat pump hot water supply and heating system

The invention claimed is:
 1. An operation planning method performed in asystem including a power generation device, a first electric load whichoperates using power generated by the power generation device, and asecond electric load which generates heat using power generated by thepower generation device, the second electric load including a heatgeneration unit which generates heat using power generated by the powergeneration device, a heat storage unit which stores heat generated bythe heat generation unit, a first radiator unit which radiates heatstored in the heat storage unit, and a second radiator unit whichdirectly radiates heat generated by the heat generation unit, saidoperation planning method being performed to design an operation planfor the second electric load, and said operation planning methodcomprising: predicting, for individual unit time periods, an amount ofpower to be generated by the power generation device, a first amount ofpower to be consumed by the first electric load, and a second amount ofpower to be consumed by the heat generation unit to generate heat to beradiated by the second radiator unit; and designing the operation planfor the second electric load to cause the second electric load tooperate during an operation period which includes, among the unit timeperiods, a unit time period in which an amount of reverse power is thelargest, the reverse power being calculated by subtracting the firstamount of power to be consumed and the second amount of power to beconsumed from the amount of power to be generated.
 2. The operationplanning method according to claim 1, wherein the power generationdevice is a photovoltaic device, in the predicting, an amount of heat tobe radiated in reverse flow standby by the first radiator unit during areverse flow standby time period is further predicted, the reverse flowstandby time period being a time period in which the amount of power tobe consumed exceeds the amount of power to be generated, and in thedesigning, an operation plan for the heat generation unit to operateduring the operation period is designed such that an amount of heat isstored in the heat storage unit, the amount of heat corresponding to theamount of heat to be radiated in reverse flow standby as predicted inthe predicting.
 3. The operation planning method according to claim 2,wherein in the designing, the operation plan is designed for theoperation period which is determined by selecting one or more of theunit time periods in descending order of the amount of reverse poweruntil a total amount of time of the one or more selected unit timeperiods exceeds an amount of time required for the heat generation unitto generate the amount of heat corresponding to the amount of heat to beradiated in reverse flow standby.
 4. The operation planning methodaccording to claim 3, wherein in the designing, a reverse powerthreshold value is set to be the amount of reverse power with the lowestvalue among the one or more selected unit time periods, and theoperation plan is designed such that operation of the heat generationunit is started at a point in time at which the reverse power, asactually measured, becomes equal to or exceeds the reverse powerthreshold value during the operation period.
 5. The operation planningmethod according to claim 4, wherein in the designing, the operationplan is further designed such that operation of the heat generation unitis stopped at a point in time at which the amount of heat correspondingto the amount of heat to be radiated in reverse flow standby isgenerated during the operation period.
 6. The operation planning methodaccording to claim 2, wherein the heat storage unit includes a thermalstorage medium whose temperature varies according to the amount of heatstored, the heat generation unit includes a heat pump capable of heatingthe thermal storage medium to a first temperature, and a heater capableof heating of the thermal storage medium beyond the first temperature,and in the designing, with respect to the amount of heat correspondingto the amount of heat to be radiated in reverse flow standby, theoperation plan is designed to cause the heat pump to generate an amountof heat until the thermal storage medium reaches the first temperature,and to cause the heater to generate an amount of heat after the thermalstorage medium reaches the first temperature.
 7. The operation planningmethod according to claim 2, wherein in the predicting, the amount ofheat to be radiated by the radiator unit during the reverse flow standbytime period is predicted as the amount of heat to be radiated in reverseflow standby, the reverse flow standby time period being a time perioddelimited by a reverse flow standby start time and a predeterminedassumed time at which the radiator unit will stop radiating heat, andthe reverse flow standby start time being a time when the amount ofreverse power changes from a positive value to a non-positive value. 8.An operation method performed by a heat pump hot water supply andheating system including a photovoltaic device and a heat pump hot watersupply and heating device, the heat pump hot water supply and heatingdevice including: a heat pump which generates heat using power generatedby the photovoltaic device; a hot water supply tank which stores hotwater heated using heat generated by the heat pump; and a heating devicewhich heats a space using heat generated by the heat pump, the systemincluding an operation planning device, and the operation methodcomprising control of the system by the operation planning device, thecontrol including: predicting an amount of power to be generated by thepower generation device, a first amount of power to be consumed by anelectric load, and a second amount of power to be consumed by the heatpump to generate heat to be radiated by the heating device; calculatingan amount of reverse power by subtracting the first amount of power tobe consumed and the second amount of power to be consumed from theamount of power to be generated; predicting an amount of heat requiredin a reverse flow standby time period during which the amount of reversepower is zero; and designing an operation plan which causes the heatpump hot water supply and heating device to operate to store thepredicted amount of heat during an operation period which includes atime period in which the amount of reverse power is the largest.
 9. Theoperation method performed by the heat pump hot water supply and heatingsystem according to claim 8, wherein in the designing, a heat storagetarget temperature to store the predicted amount of heat is determinedand a reverse power threshold value is set to the amount of reversepower with the lowest value among the operation periods.
 10. Theoperation method performed by the heat pump hot water supply and heatingsystem according to claim 9, the controlling further comprisingperforming control based on the heat storage target temperature and thereverse power threshold value determined and set in the designing,wherein in the controlling, operation of the heat pump hot water supplyand heating device is started at a point in time at which the reversepower as measured reaches or exceeds the reverse power threshold valueduring the operation period, and operation of the heat pump hot watersupply and heating device is stopped at a point in time at which thepredicted amount of heat is generated during the operation period. 11.The operation method performed by the heat pump hot water supply andheating system according to claim 10, wherein in the designing, the heatstorage target temperature for storing the predicted amount of heat in ahot water supply tank is determined, and a thermal storage medium insidethe hot water supply tank is heated to a first temperature with a heatpump included in the heat pump hot water supply and heating device, thenthe thermal storage medium is heated to a second temperature which ishigher than the first temperature with a heater installed in the hotwater supply tank.
 12. The operation method performed by the heat pumphot water supply and heating system according to claim 10, wherein theheat pump hot water supply and heating device includes a hot watersupply and heating control device, and the hot water supply and heatingcontrol device is set up to receive operation information for the heatpump hot water supply and heating device from a remote control as wellas from the operation planning device, and when operation information isreceived from the operation planning device and from the remote control,the hot water supply and heating control device gives the operationinformation from the operation planning device priority over theoperation information from the remote control, and controls the heatpump hot water supply and heating device based on the operationinformation from the operation planning device.
 13. The operation methodperformed by the heat pump hot water supply and heating system accordingto claim 12, wherein the operation information is an operation mode forthe heat pump hot water supply and heating device, and a hot watersupply temperature setting for the hot water supply tank.
 14. Theoperation method performed by the heat pump hot water supply and heatingsystem according to claim 11, wherein the heat pump hot water supply andheating device further includes a heat exchanger which facilitates heatexchange between a refrigerant in the heat pump and the thermal storagemedium, and a switching device which switches supply of the thermalstorage medium supplied from the heat exchanger to one of the hot watersupply tank and the heating device, and in the controlling, when theswitching device is switched to the heating device and the temperatureof the thermal storage medium is below the first temperature at a pointin time at which operation of the heat pump hot water supply and heatingdevice starts, the switching device switches to the hot water supplytank.